1. Field of the Invention
The present invention relates to a multistage connector, formed by combining constituent connectors with each other in a multistage, for use in a wire harness of an automobile.
2. Description of the Related Art
With the rapid increase of the installation of electric parts on the automobile in recent years, connectors have been increasingly used to accommodate terminals connected with the wire harness. In this situation, proposals of a multistage connector in which constituent connectors are vertically combined with each other have been made to accomplish an intensive arrangement of connectors.
An example of a conventional multistage connector disclosed in Japanese Patent Laid-Open Publication No. 2-148583 is described below with reference to FIGS. 7A and 7B. In order to vertically combine constituent connectors 1, 2, and 3 with each other, the connectors 1, 2, and 3 are slid in a direction as shown by arrows of FIG. 7A by means of guide projections 4 and guide grooves 5 formed on the upper and lower surface thereof, respectively so as to fix the connectors 1, 2, and 3 to each other vertically. Then, a cover 6 is placed on the connector 3 and projections 7 formed on both side surfaces of each of the connectors 1, 2, and 3 are inserted into locking openings 6b formed on both side surfaces 6a of the cover 6.
The cover 6 is indispensable in the above-described multistage connector and combining operation takes time and labor.
More specifically, it is necessary to slide the connectors 1, 2, and 3 to pile them one on the other and then, mount the cover 6 on them in a direction perpendicular to the connector-sliding direction. That is, two-stage operation is required. In addition, a terminal accommodated in the connector is locked by only a locking portion formed in a terminal-accommodating chamber and the connectors have no mechanism for additionally holding the terminal. Thus, when an electric wire connected with the terminal is pulled in combining the connectors with each other by sliding them, there is a possibility that the terminal slips out from the connector.